Apparatus for clamping mirrorscript originals in duplicating machines and method relating thereto



Nov. 5, 1940. w. RlTZERFELD 2,220,282

APPARATUS FOR CLAMPING MIRROR-SCRIPT ORIGINALS IN DUPLICATING MACHINES AND METHOD RELATING THERETO r Filed Oct. 3, 1938 3 Sheets-Sheet l l0 venlar W lhelm R 1'2 zerfefd Affol hey 3 Sheets-Sheefi 2 RITZ ERFELD -SCRIPT ORIGINALS IN DUPLICATING Filed Oct.

MACHINES AND METHOD RELATING THERETO Nov. 5, 1940.

APPARATUS FOR GLAMPING MIRROR r m w m y mlbelm fiilzerfda I C M Attorney 2,220,282 LS IN DUPLICATING Nov. 5, 1940- w. RITZERFELD ING MIRROR-SCRIPT ORIGINA APPARATUS FOR CLAMP MACHINES AND METHOD RELATING THERETO Filed Oct. 5, 1958 3 Sheets-Sheet 3 Aitome y Patented Nov. 5, 1940 APPARATUS FOR CLAIWPING MIRBOB- SCRIPT ORIGINALS IN DUPLICATING MA- CHINES AND METHOD RELATING THERE- Wilhelm Ritzeri'eld, Berlin, Germany Application October a, 1938, Serial No. 232,934

' In Germany October I, 1937 13 Claims.

The present invention relates to an apparatus for clamping originals bearing copyable mirrorscript to theprinting drum of a duplicating machine printing onto clear sheets previously moistened with a readily volatilizing solvent and fed into the machine bymeans of feed rollers, and to an improved method of clamping such originals.

Heretofore, in conventional spirit duplicating machines of the described character, the original or master sheet bearing copyable mirror-script was clamped to or was released from the printing drum in a position other than the initial position or the normal position of rest of the print ing drum. As a matter of fact, the ,clamping operation was performed only after the printing drum has already traveled a considerable distance from its initial position of rest and it was generally carried out either before obtaining or after leaving said initial position of rest. Of course,'after the clamping operation was completed in such intermediate position, the printing drum had to be rotated along a further and substantial angular displacement before the first printing operation could be carried out or could be started from the initial position of rest. Obviously this type of operation was not only complicated and troublesome but also has caused a very substantial loss of time. Although this difiiculty was felt in the art for some time and various suggestions and proposals were made to eliminate and to avoid the same, none, as far as I am aware, of these suggestions and proposals was completely satisfactory and successful when carried into practice on a practical and commercial scale.

I have discovered a simple and completely satisfactory solution of the outstanding problem.

It is an object 'of the present invention to provide aclamping apparatus for duplicating machines of the described character which is free from the disadvantages and inconveniences of conventional clamping devices.

It is another object of the present invention to provide an improved clamping apparatus particnlarly for duplicating machines of the spirit type which is capable of carrying out the clamping or releasing operation substantially in the initial position of rest of the printing drum.

It is a further object of the present invention tc provide a novel and improved clamping appaior spirit duplicating machines involving a charming bar which is automatically displaced int: the sheet inserting position while the printing drum is in its initial position of rest.

The invention also contemplates a method of automatically inserting into and releasing .from the clamping device of a printing drum master sheets bearing copyable mirror script, in the original or rest position of such printing drum.

It is also within contemplation of the invention to provide a clamping apparatus for clamping mirror-script originals, to the printing drum of spirit duplicating machineswhich is'simple in construction, easy and fool-proof in operation andwhich may be manufactured on a practical and commercial scale at a low cost.

Other and further objects and advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which:

Fig. 1 illustrates a side elevational view, somewhat fragmentary and diagrammatic in character, of a clamping apparatus embodying the principles of the present invention;

Fig. 2 depicts a similar view of the clamping apparatus and of its cooperating parts in the operative position;

Fig. 3 shows a plan view of the clamping apparatus depicted in Figs. 1 and 2, having parts in horizontal section;

Fig. 4 illustrates a side elevational view, somewhat fragmentary, of a printing drum and of a modified clamping apparatus associated therewith involving a controlling cam which may be selectively actuated manually or by a movable part of the machine;

Fig. 5 depicts a fragmentary front elevational view of the printing drum and clamping apparatus shown in Fig. 4; I

Fig. 6 shows a side elevational view of an apparatus for actuating the various devices and elements of a duplicating machine in a mutually dependent and predeterminedmanner;

Fig-7 is a fragmentary front elevational view having parts in section of the apparatus depicted in Fig. 6, and 1 Fig. 8' is a fragmentary top elevational view.

having parts in section, of the apparatus de-' picted in Figs. 6 and 7.

Broadly stated, according to the principles of the present invention, the leading edge ,ofthe copyable mirror-script original or mastersheet is introduced into the open clamping device while the printing drum is in its original'position of rest. In addition to this,-in accordance with the principles of the invention, means are provided for automatically opening the clamping device 5 before or after arrival of the printing drum into springs 2a.

number of rotations of the printing drum, and to automatically close the clamping device before or after leaving this initial position. According to the invention, the clamping means are actuated by means of a cam-like member pivoted independently from-the printing drum which preferably becomes operative during the last printing rotation of the printing drum or duringthe time while the last copy sheet of the series to be printed with the same original is passing through the machine. I have also found that important advantages may be obtained by feeding the master sheet to the clamping device of the printing drum through asteeply inclined guiding of and in the direction. of rotation of the printing drum. In this manner it is possible to drop the original into the opened clamping device of the drum by gravitational action without requiring any further actuating members.

The invention will now be more fully described to those skilled in the art in conjunction with a few preferred embodiments thereof.

Referring now more particularly to Figs. 1 to 3,

a preferred embodiment of the'invention is illustrated. Reference character I denotes the printing drum of a duplicating machine in which is mounted a radially displaceable clamping bar 2 retained in its closed position "by means of drum I there is rotatably mounted an actuating shaft 4 which is adapted to lift the clamping bar in the radial direction by means of a plurality of levers 3. At one end of shaft 4 and at one side of the printing drum I, a lever 6 is, rigidly mounted on the shaft, preferably having a small roller 5 rotatably mounted on its free end. On the side wall 1 of the duplicating machine, a cam-lever 8, preferably double-armed, is pivotally mounted in a pin or pivot 8a, and is j'ointedly-preferably toggle-lever like-connected by means of a pin 9b with a manually operative actuating lever 9 pivoted in pin 9a. In addition to this, a spring I!) presses against pin 9b of jointedly connected levers 8 and 9 so that said levers are'positively maintained in either of their end positions.

Pin or axle 9b of jointed levers 8 and 9 also carries one end of a link I I, having its other end connected to an'intermediate portion of a stop lever I2. Link II is adapted to lift up stop lever I2 and to bring its free end l2a into the path of a pin i3 provided on the side wall of the printing drum, as this will be readily observed in Figs. 1 and 2.

F From the foregoing description, the operation of my improved clamping apparatus will be readily understood by those skilled in the art. In Fig. 1, the clamping apparatus and cam 8 are illustrated in the position of rest thereof. When it is desired to insert a new master sheet, actuating or control lever 9 is depressed in the direction of tion, roller 5 of lever B will run up on the cam surface of cam 8 whereby lever B will be dis- 2 in the open position thereof. In this position- In the side walls of the printing 4 locking disk 2|.

of the clamping device and of its cooperating elements, the used master sheet may be removed and a new master sheet may be introduced by means of a feed table or tray IS. The leading edge of the new master sheet will fall into the opened clamping bar under the effect of its own weight and in the direction of rotation of the printing drum. During the further rotation of the printing drum, pin l3 strikes against stop [2a so that lever I2 is displaced downwardly and snaps over jointed levers 8 and 8 whereby all of the cooperating members of the clamping mechanism are returned into their normal position of rest depicted in Fig. 1. In this position of rest, cam 8 is inoperative and also pin l3 and stop |2a are in a position in which they are of no effect upon one another. Clamping bar 2 is automatically closed under the influence of springs 2a and imprisons the new master sheet.

In the modified embodiment of the invention shown in Figs. 4 and 5, a bell crank lever I6 is pivotally mounted in a shaft or pin 8a provided in cam lever 8. Bell crank lever l6 bears an axle or pin I! at one of its ends, which presses against the shaft 91) of the jointed levers 8 and 9. At l8, moistening device l9 has a link 20 connected thereto, said link being connected with some lost motion to bell crank lever l6 by means of a pin iBa. In this modified embodiment, cam 8 is automatically made inoperative as soon as the moistening device is lowered. In this case, link 20 causes bell crank lever IE to turn and to push the jointed connection of levers 8 and 9 over into its other end position by the pressure of pin I! on axle 91). Thus, the cooperating parts of the clamping mechanism are automatically returned into their normal position of rest depicted in Fig. l.

Figs. 6 to 8 illustrate the arrangement for starting and stopping the printing drum and the parts cooperating with this starting and stopping mechanism. Printing drum i is provided with a locking disk 2| having a depression Zia therein. In addition'to this, a bell crank lever 24 is pivotally mounted on a pin 22 mounted on the side wall 1 of the duplicating machine. Lever 24 is under the influence of a spring 241) and has one of its ends connected by means of a laterally protruding pin 23a to a foot-controlled release member 23, while its other end is jointeclly connected by means of a pin 24a to a slide member 25. To slide member 25 is operatively connected a bolt 26 by means of a spring-urged pin 21, said' bolt being adapted to engage depression- 21a of Spring-urged pin 21 is slideably arranged in a slot 28. Reference character 29 denotes a bell crank-shaped pawl, under the influence of a spring 2%, rotatably mounted in a pin 29a in the side surface of printing drumJ. One end, 29c,-of pawl 29 bears against the free end of slide member 25 while its other end 29d is provided with an extension 29c adapted to engage the teeth of a ratchet disk 30 rigidly mounted on the shaft of printing drum l. Ratchet disk 30 is maintained in continuous rotation by the main drive of the machine and will cause rotation of the printing drum when the teeth of the ratchet-disk 30 are engaged by extension 29a. Reference character 3| denotes a locking lever pivotally mounted in a pivoting pin 3Ia in the side wall I of the duplicating machine under the influence of a spring- 3| b for locking lever 32 'which is mounted on shaft l8 of moistening device l9. Moistening device I9 is under the influence of one or more springs l9a. Lever 32 is provided with a slot 32b at the upper end thereof which engages with some lost motion a pin 32a mounted on the lower end of a lever 33 pivoted in 33a and bearing a roller 33b secured thereto by a screw 36. This roller is adapted to cooperate with a cam 34 mounted on the side wall of the printing drum and with a surface 35a provided on extension 35 of cam 34.-

From the foregoing description the operation of this modified embodiment of the invention will be readily understood. When the foot-controlled release member 23 is depressed, bell crank lever 24 is displaced in the direction of the arrow, and withdraws slide member 25 so that end 290 of pawl 29 becomes free and under the influence of spring 29b will engage ratchet disk 30. This will cause printing'drum I to rotate. At the same time, pin 23a of the release member 23 will press locking lever 3| downwardly and free lever 32 so that moistening device i9 is pressed by spring i9a against the sheet to be printed onto. Lever 32 also rotates lever 33 in the direction of the arrow and into the path of entension 35 of cam 34. When after the completion of the rotation 5 of the drum, surface 35 strikes a'gainst roller 33b,

this will return lever 33 into its original position and by means of lever 32 will lift moistening device l9. Therefore, locking lever 3| will be also returned behind lever 32 and will lock the moistening device in.the raised position.

When slide member 25 is withdrawn, this will also cause withdrawal of bolt 26 by means of pin 2'! so that the printing drum l is released and is ready for rotation as, soon as pawl 29 engages ratchet disk 30.

The apparatus described in the foregoing makes it possible to automatically lower moistening device IS on the copy sheet to be printed onto upon actuation of the foot-controlled release 40, member, and at the same time to release the printingdrum for rotation and to close clamping bar 2. i

Although the present invention has been described in connection with a few preferred em- 45lbodiments thereof, variations and modifications may be resorted to by those skilled in the art without departing from the principles of the 0 lever independent from said drum having a cam surface adapted to be displaced intothe path of said control mechanism to actuate said clamping bar near the original position of said drum, a manually operable actuating lever jointedly 65 connected to said cam lever for displacing the same from its inoperative into its operative position, a reset arm operatively associated with said cam and actuating levers, and a pin on said drum adapted to strike against said reset arm in the '7 operative position of said cam and actuating levers and to return the same into their normal position of rest.

2. In, a duplicating machine, the combination comprising a printing drum, means for rotating 75 said drum, a clamping bar displaceable in said printing drum for clamping a copyable original, a control mechanism mounted on said drum for opening and closing said clamping device, a cam lever independent from said drum having a cam surface adapted to be displaced into the path of said control mechanism to actuate said clamping bar near the original position of said drum, a manually operable actuating lever jointedly connected to said cam lever for displacing the same from its inoperative into its operative position. means including a slotted pin and a resilient element for positively retaining said jointed cam and actuating levers in either of their extreme positions, a reset arm operatively associated with said levers, and a pin on said drum adapted to strike against said reset arm in the operative position of said levers and to snap the same over into their normal position of rest.

3..In a duplicating machine, the combination comprising a printing drum, means for rotating said drum, a clamping bar radially displaceable in said printing drum for clamping a copyable original, a control mechanism mounted on said drum foropening and closing said clamping device, a cam lever having a cam surface adapted to be displaced into the'path of a control member of said mechanism to actuate said clamping bar near theoriginal position of said drum, a flattened surface on said cam for maintaining said control member stationary in the openposition of said clamping bar, a manually operable actuating lever jointedly connected to said cam lever for displacing the same from its inoperative into its operative position, a reset arm operatively asso-- ciated with said cam and actuating levers, and a pin on said drum adapted to strike against said reset arm in the operative position of said cam and actuating levers and to return the same into their normal position of rest.

4. In a duplicating machine, the combination comprising a printing drum, means for rotating said drum, a clamping device displaceable in said printing drum for clamping a copyable original, a control mechanism mounted on said drum for opening and closing said clamping device, 'a cam lever independent from said drum having a cam surface adapted to be displaced into the path of said control mechanism to actuate said clamping device near the original position'of said drum, .a manually operable actuating lever jointedly connected to said cam lever for displacing the same from its inoperative into its operative position, snap-action means for positively retaining said cam and actuating levers in either of their extreme positions, and a reset mechanism for said cam and actuating levers, said reset mechanism including means operatively associated with a pe- -riodically actuated part of the duplicating masurface adapted to be displaced into the path of said control mechanism to actuate said clamping bar near the original position of said drum, a manually operable actuating lever jointedly connected to said cam lever for displacing the same from its inoperative into its operative position,- and a reset mechanism for returning said cam and actuating levers into their normal position of rest, said reset mechanism being'ope'rable by the displacement of the moistening device of the duplicating machine.

6. In a duplicating machine, the combination comprising a printing drum, means for rotating said drum, a clamping bar displaceable in said printing drum for clamping a copyable original, a control mechanism mounted on said drum for opening and closing said clamping device, a cam lever independent from said drum having a cam surface adapted to be displaced into the path of said control mechanism to actuate said clamping bar'near the original position of said drum, a manually operable actuating lever jointedly connected to said cam lever for displacing the same from its inoperative into its operative position, and a reset mechanism for said jointedly connected cam and actuating levers, said reset mechanism including a bell crank lever operatively associated with a-periodically actuated part of the duplicating machine and having a striking surface adapted to snap over said cam and actuating levers from their operative into their rest position.

7. In a duplicating machine, the combination comprising a printing drum, means for rotating said drum, a clamping device displaceable in said printing drum for clamping a copyable original, a control mechanism mounted on said drum for opening and closing said clamping bar, a cam' lever independent of said drum having a cam surface adapted to be displaced into the path of said control mechanism to actuate said clamping device near the original position of said drum, a manually operable actuating lever jointedly connected to said cam lever for displaclng the same from its inoperative into its operative position, snap-action means for positively retaining said cam and actuating levers in either of their extreme positions, a reset mechanism for said cam and actuating levers, said reset mechanism including means operatively associated with aperiodically actuated part of the duplicating machine and being adapted to snap over said cam and actuating 'levers into their position of rest, and means for automatically locking the printi g drum in its normal position of rest.

8. In a duplicating machine, the combination comprising a printing drum, driving means for rotating said drum, a clutch intermediate to said driving means and said drum, a moistening device, a clamping device for a master sheet on said printing drum, a control mechanism mounted on said drum for opening and closing said clamping device, a cam lever having a cam surface adapted to be displaced into the path of said control mechanism to actuate said clamping device near the original position of said drum, a manually operable actuating lever jointedly connected to said cam lever for displacing the same from its inoperative into its operative position, snap-action means for positively retainingsaid cam and actuating levers in either of their extreme positions, a reset mechanism for said cam and actuating levers, said reset mechanism including means operatively associated with a periodically actuated part of the duplicating machine and being adapted to snap over said cam and actuating levers into their normal position of rest, means for automatically locking said drum in its initial position, and means for initiating operation of said moistening device, of said clamping device, of said locking means and of said clutch in predetermined sequence,

9. In a duplicating machine, the combination comprising a printing drum, a clamping device arranged on said drum for clamping a master sheet, a control mechanism for opening and closing said clamping device, said control mechanism having elements mounted on said drum and having elements mounted independently from said drum, an inclined feeding plate for said master sheet located before said drum constructed and arranged to cause said master sheet to slide into the opened clamping device, and partly manually and partly automatically operable actuating means for actuating said control mechanism when said printing drum is in its original position beginning the printing operation, said actuating means including a cam adapted to be introduced into the path of a member of said control mechanism.

10. In a duplicating machine, the combination comprising a printing drum, a clamping device on said drum for clamping a copyable original, a control mechanism mounted on said drum for opening and closing said clamping device, a cam lever independent of said drum having an inoperative position and being adapted to be displaced into an operative position into the path of said control mechanism to actuate said clamping device in proximity to the original position of said drum, means for displacing said cam lever into its operative position, snap action means for positively holding said cam lever in either of said positions, and resetting means operatively associated with said cam lever operable by said printing drum in a predetermined position thereof to snap back said cam lever into its inoperative position.

11. Ina duplicating machine, the combination comprising a printing drum, a clamping device on said drum for clamping a copyable original, a control mechanism mounted on said drum for openingand closing said clamping device, a cam lever independent of said drum having an inoperative position and being adapted to be displaced into an operative position into the, path of said control mechanism to actuate said clamping device in proximity to the original position of said drum, snap action means for holding said cam lever in either of said positions, manually operable elements for snapping over said cam lever into its operative position, and resetting means operatively associated with said cam lever operable by said printing drum in a predetermined position thereof to return said cam lever and said manually operable elements into their inoperative position.

12. The method of copying mirror-script originals clamped to the circumferential surface of a printing drum onto clear sheets previously moistened with a readily volatilizing solvent which comprises opening the clamping mechanism in the normal position of rest of the printing drum beginning the printing operation, feeding said mirror-script original exclusively by gravity to said open clamping mechanism over a steeply inclined feeding surface codirectionally with the rotation of said drum and during the time while said drum is in saidstationary position, closing said clamping mechanism to imprison the leading edge of said original, displacing said original on the drum along a circular path toward the printing region, and feeding a moistened copy sheet toward said printing region substantially synchronously with the displacement of the original and during the same revolution of said printing drum.

13. The method of copying mirror-script originals clamped to the circumferential surface of a. printing drum onto clear sheets previously moistened with a readily volatilizing solvent which comprises opening the clamping mechanism in the normal position of rest of the printing drum beginning the printing operation, feeding said mirror-script original exclusively by gravity to said open clamping mechanism over a steeply inclined feeding surface codirectionally with the rotation of said drum and during the time while said drum is in said stationary position, closing said clamping mechanism to imprison the leading edge of said original, displacing said original on the drum along a circular path toward the printing region, feeding a moistened copy sheet toward said printing region during the same revolution of said drum', and so controlling the displacement of said original and of said copy sheet that their leading edges arrive simultaneously to the printing region.

WILHELM RI'I'ZERFELD. 

